Electrical control device



Sept. 12, 1939. AH. A. DOUGLAS 2,172,934

ELECTRICAL CONTROL DEVICE Filed Feb. 26, 1955 Hzxg A.. uglaa lk vins-TOR BIM, www@ ATToRNxxs Patented Sept. l2, 1939 .UNITED` STATES PATENT GFFI'CE Harry A. Douglas, Bronson, Mich., assignor to Kingston Products Corporation, a corporation of Indiana Application February 26, 1935, Serial No.. 8,3164

Claims.

My invention relates' to electrical control devices and tov electrical contact and terminal means which may' form apart of electrical control devi'ces. One of the uses' to which my in- 5 vention may be put is in connection with electric switches and the like, and a more specific use is in connection with the control of electrical resistances. 'The principal object of my invention is to provide new and. improved electrical devices l0 and means of the hereinbefore mentioned types. In the drawing accompanying this specication, and forming a part of this application, I have shown, for purposes of illustration', one form which my invention may assume. In the drawf ing:

Figure 1 is a vertical sectional view of one embodiment of my invention as it may be applied in a resistance control switch,

Figure 2 is a rear elevation of the base of the Switch shown in Figure 1, with contact means and a resistor assembled' therewith,

Figure 3 is a fragmentary sectional view taken along the line 3-3 of Figure 2, looking in the dir'ction of the arrows,

Figure 4 is a fragmentary sectional View taken along the line 4-4 of Figure 2, vlooking in the direction of the arrows, and

Figure 5 is a. perspective view of a detail, with certain parts disassembled.

Referring to Figure 1 of the drawing a panel I0 has mounted thereon a switch casing II, of cup-shape, having a bottom I2 and a tubular portion I3 extending therefrom. Fastened to the bottom I2 in any suitable manner is a threaded nipple I4 extending through an aperture in the panel I0, and engaged by a nut I5. A shaft IB is disposed through the nipple I4 and is provided at one end with an operating handle I'I. At the other end the shaft I6 is provided with a laterally 0 extending member |8 drivingly connected in any suitable manner to an insulating carrier I9.

The insulating carrier I9` carries a contact member 20 which may be of any suitable form and in this instance is shown as extending from the center o-f the face of the contact carrier I9 tothe radially outer edge thereof, as indicated by the dotted lines 28 in Figure 2. The contact 20 may be provided with depressions, one of which, 2|, is Visible in Figure 1, these depressions being provided for cooperation with relatively stationary contact means mounted on a base 22, The base 22 is adapted to be received by the open end of the casing II, and fastened to the casing II in any suitable manner.

` The-base-ZZ is provided with'a' generally cen- (Cl. Zim-166) tral boss 23, in which is reciprocably mounted a contact means 24, having a construction substantially similar to that disclosed in my copending application Serial Number 8,315, led February 26, 1935; since formally abandoned in favor of my substitute co-pending application, Serial Number 205,299, led April 30, 1938. The contact means 24 is here shown of U-shape and desirably formed to that shape from sheet stock, which may be iron, steel, or other suitable metal. The U-shaped contact means 24 has legs 25,26, the leg 25 being adapted to be received in an aperture 2l, extending axially through the base 22 and the boss 23 thereof. The leg 26 is adapted to be received in an aperture 28, extending through the base 22 and the boss 23 thereof. As will be seen from Figure 2, the apertures 21, 28 are parallel to each other and at right angles to a diameter of the base 22. Also, the aperture 2l is wider than the aperture 28, and both apertures conform in cross-section and position so as to rcciprocably receive the legs 25, 26 of the U-shaped contact means 24.

The apertures 21, 28 are connected, at the inner face of the base 22, by a recess 29 extending from the inner face of the base 22 part way into the boss 23 and terminating in a bottom 30. The width of the recess 29, asviewed in Figure 2, may be the same as that of the aperture 28.

The contact means 24 carries a contact 3|, adapted to cooperate with the depression 2| in the contact 2U. The contact 3| is formed similarly to a rivet, the head serving to provide an electrical contact surface and the shank passing through an aperture in the bight of the U-shaped Contact means 24. The end'of the shank of the contact 3| is upset or riveted and forms a projection 32, which also serves to position or locate one end of a spring 33, the other end of which bears against the bottom 30 of the recess 29,

The contact means 24 is provided with conductor terminal connecting means comprising a Screw'34 cooperating with'a threaded hole in the leg 25, the leg`25 being longer than the leg 26 and extending away from theouter face of the boss 23. A conductor 36 is here shown as clamped between the head of the screw 34 and a lock washer 35, although the conductor 35 may be interposed between the washer 35 and the leg 25. The washer 35 is4 provided at the periphery of its central aperture with serrations 31, extending` laterally from both faces of the Washer. The washer`35' is also'provided with a lateral projection 38'adapted to extend through a hole 39 inthe leg 25, ytoI ltherebyprevent turning-of the washer. The lateral extension 38 may also serve to limit motion of the contact means 24 to the right as viewed in Figure 1, by engagement of the projection 38 with a shoulder 40 cut back from the outer face of the boss 23.

The boss 23, as may be seen in Figure 2, has an arcuate generally axially extending surface 4| concentric With the base, bounding a portion of the transverse section of the boss, and another arcuate surface 42 of greater radius than the arcuate surface 4|, also concentric With the base, and merging in any suitable Way with the arcuate surface 4|. The arcuate surface 42 serves to form the radially inner side of an arcuate recess 43 in the outer face of the base 22. As shown in Figure l, the recess 43 has a bottom 44 arcuate in radial cross-section. The radially outer side 45 of the recess 43 is formed in part by the inner periphery of an axially extending arcuate ange 46 provided on the base 22. The terminal ends of the arcuate recess 43 are formed by bosses 41, 48 on the base 22.

A resistor 49 is disposed in the arcuate recess 43, the resistor 49 comprising in this instance a helical resistance Wire flexed to arcuate form and having terminal ends 50, 5| connected to contact means 52, 53 respectively.

The contact means 52, shown in detail in Figure 3, is reciprocably mounted in the boss 41 and comprises a body portion 54 of suitable metal. The body portion 54 has an axial bore 55 extending from one end thereof a desired distance to- Ward the other end, and a transverse aperture 56 near the other end. The bore 55 communicates with the transverse aperture 56, the bore 55 being constricted at the point of communication to form a seat 51 for a ball 58.

The body portion 54 of the contact means 52 is oblong in cross-section, the transverse aperture 56 having its axis extending approximately along a diagonal of the oblong cross-section, as may be seen in Figure 2. The corners of the body portion 54 are chamfered to form four rounded surfaces 59. The chamfers 59 do not extend the entire length of the body 54, but terminate near one end of the body 54 to thereby form four shoulders 69, as may be seen most clearly in Figure 5. The shoulders 60 serve the purpose of retaining at the open end of the axial bore 55 an end closure 6|. The end closure 6| is here shown as comprising a dome-shaped portion merging into a radially extending flange 8| from which extends in an axial direction a cylindrical flange 62. The inside diameter of the cylindrical flange 62 is desirably of the same diameter initially as the diameter of a circle circumscribing the apexes of the four shoulders 6|). The radially extending flange 8| is adapted to abut the right hand end of the body 54, as viewed in Figure 3, and the peripheral edge of the flange 62 is spun radially inwards around the projections formed by the shoulders 60, and against the shoulders 66, thereby securely fastening the end closure 6| to the body 54. The domeshaped portion 80 ofthe end closure serves to provide a contact surface, and ,if desired the closure 6| may be made of a different metal from the body 54, a desirable metal being brass.

Within the bore 55 of the body 54 is disposed a helical spring 63, one end of which engages the end closure 6| and the other end of which en gages the ball 58, thereby biasing the ball toward the seat 51.

The body 54 of the contact means 52 is adapted to be reciprocably received in an aperture64 in the boss 41, the aperture 64 being of the samebody 54, the conductor terminal 61 being provided With an annular furrow 68, into which the ball 58 is urged by the spring 63. The end of the conductor terminal 61 is here shown as having a frustro-conical end, which is sWedged to the conductor within the terminal 61, as indicated by the swedge indentations 10.

Extending axially from the end of the body 54 is a stud 1| of cylindrical contour and less in cross-section than the body 54. The stud 1| is provided with an axially extending diametrical slot 12, the walls of this slot being spaced such distance as to receive and hold the terminal 5U of the resistor 49. The halves of the stud 1| may be bent toward each other so as to pinch the terminal 50 between the Walls of the slot 12, as shown most clearly in Figure 5. In the embodiment illustrated, when the contact means is as-V sembled with the base 22, the slot 12 is vertical, as viewed in Figure 2, as is also the axis of the conductor terminal receiving aperture 56. The slot 12 thus is substantially on a diagonal of the cross-section of the body 54.

The Contact means 53 comprises a body portion 13, of oblong cross-section similar to that described in connection with the body of the contact means 52, and has an axial bore 14 terminating short of one end of the body 13. The body 13 is chamfered in the same manner as already described in connection with the contact means 52, leaving four shoulders 11, which serve as a means of attaching an end closure 15, indentical with the end closure 6|, to the body 13, by spinning a flange 16, the same as the flange 62 of the end closure 6|, over the shoulders 11 The contact means 53 is reciprocably mounted in the boss 48, an aperture 18 in the boss 48 being formed to receive the body 13. The cross-section of the aperture 18 is of the same form as the cross-section of the body 13. The body 13 is provided With an axially extending stud 16 having a slot 82 formed therein in a manner similar to that of the slot' 12 in the stud 1|. The slot S2 is adapted to receive the terminal 5| of the resistor 49, and the halves of the stud 19 may be bent toward each other, so as to pinch the terminal 5|, as already described in connection with the termi* nal 50.

In the disclosed embodiment no connection to an external conductor terminal, such as the terminal 61, is necessary in connection with the con tact means 53, and consequently, the contact means 53 does not include a snap terminal means comprising a ball 53 and a transverse aperture 56, such as described in connection with the contact means 52. has disposed around the body 13 a helical spring 83 adapted to be received in a recess 84 ccMef- However, the contact means-53 also,I

with the relatively movable contact element 2U, also perform the function of making electrical connection to the resistor 4Q and mechanically supporting it in the recess t3.

When the parts are assembled as shown in Figure 1, the contact means 24, 52, and 53 are biased toward the Contact carrier i9, the contact Si remaining in contact with the` depression 2i of the contact 2B in any position of the operating handle H, whereas the Contact elements i, 'i5 are either in Contact with a depr-ession, similar to the depression 2I, in the radial end of a contact 20, or in contact with a depression in the insulating carrier I9 itself. Thus, in the position of the parts shown in Figure 2, a circuit would be established from the conductor terminal 6l tothe terminal 50 of the resistor, through the resistor 49 to the terminal 5l thereof, through the contact means 53, to and through the contact 2Q, through the contact means 24, to the conductor 36. On the other hand, if the handle l1 is thrown so that the radial end of the contact 20 contacts with the contact elem-ent 5|, a circuit is estab lished from the conductor terminal $1, through the contact means 52, through the contact 28, through the contact means 24, to the conductor 36, thereby eliminating the resistor 49 from the circuit.

In View of the foregoing it will be obvious to those skilled in the art that my invention may be embodied in other constructions wherein the elements may assume a variety of forms, Variously changed and modified within the spirit of the invention.

In general it will be clear to those skilled in the art that the features of my invention need not ali be used in one embodiment, and may be individually or collectively variously changed and modified, without departing from the spirit of the invention, or sacrificing all of the advantages thereof, and particularly, that my invention is not limited to conductor terminals of the plug type, but that the -term conductor terminal is to be considered generic, including for example merely a portion of the conductor wire itself, and accordingly that the disclosure herein is illustrative only, and that my invention is not limited thereto.

I claim:

1. In combination: a solid metallic body portion having a longitudinal bore and a transverse bore, said longitudinal bore opening to one end of said body portion and having a portion reduced in size inwardly of said body and communicating with said transverse bore through said reduced portion, said body being of polygonal cross-sectional outline, having a predetermined number of its longitudinal corners chamfered to form shoulders near one end of said body portion; contact means spanning the open end of said longitudinal bore, and including a circular flange interengageable with said body portion shoulders; and resilient detent means interposed between said contact means and the reduced portion of said longitudinal bore, said detent means having a part cooperable with the transverse aperture and being operable to yieldably engage and hold a conductor terminal disposable Within said transverse aperture.

2. Terminal means, comprising: a metallic body, having a longitudinal aperture entering from one end, and being formed with a plurality of laterally extending projections adjacent said one end, said body also having a transverse aperture communicating with said longitudinal aperture and being adapted to receive a conductor terminal; a contact member, having a cylindrical flange circumscribing said laterally extending projections, the extremity of said ilange being crimped over said projections to hold said contact member to said body; and biasing means within said longitudinal bore, having one end bearing against said contact member, and its other end in position to yieldably engage a conductor terminal disposed within said transverse aperture.

3. Terminal means, comprising: a metallic body, having a reduced integral projection at one end, said projection being bifurcated to receive an electrical conductor, and said furcations being adapted to be clinched together to hold said conductor, said body having laterally extending projections adjacent its other end; contact means, having a cylindrical flange circumscribing said projections, the extremity of said flange being crimped over said projections to mechanically and electrically hold said body and said Contact means in assembled relation.

4. Terminal means, comprising: a body, having a longitudinal aperture entering from one end, and formed with laterally extending shoulder means at said one end, said body having also a transverse aperture communicating with said longitudinal aperture, and being adapted to receive a conductor terminal; a contact member, having a surface abutting said one end of said body, and having also a marginal flange, the free extremity of which is bent to overlie said shoulder means, so that said contact member is held against movement longitudinally of said body.

5. Terminal means, comprising: a body, having a longitudinal aperture entering from one end, and formed with laterally extending shoulder means at said one end, said body having also a transverse aperture communicating with said longitudinal aperture, and being adapted to receive a conductor terminal; a contact member, having a marginal flange, the free extremity of which is bent to overlie said shoulder means, holding said contact member assembled with said body; and biasing means, disposed within said longitudinal aperture, having one end bearing against the adjacent surface of said Contact member, and its other end in position to yieldably engage a conductor terminal disposed in said transverse aperture.

HARRY A. DOUGLAS. 

